Marin We'd Eat It! Project

This is a multi-year project in Marin County, California to train and use cattle to control invasive species. It is funded privately through a grant from a family foundation to Utah State University.
In 2006 we targeted distaff thistle (Carthamus lanatus) and Italian thistle (Cardus pycnocephalus). We began in May, by refining the process to on that would take less time (see How?) We worked with 60 heifers from the Lunny Ranch on Point Reyes in preparation for moving them to the ranch of John Wick and Peggy Rathmann in Nicasio, and with 5 heifers at Mike and Sally Gale's Chileno Valley Ranch. The Lunny cows were trained in dry lot and the Gale's cows were trained in pasture. All cows learned to eat both distaff and Italian thistles, and the Lunny cows went on to graze both successfully in pasture. Unfortunately, Mike Gale got whooping cough and so we weren't able to move his trained cows to pasture.
In 2007 about 130 of the Lunny's cows returned to the Wick Rathmann ranch in Nicasio. Twelve of the herd had been trained the previous year. Our early plan was to figure out new strategies for training all the untrained animals in pasture as we moved them on a daily basis. But when I arrived to check out the animals in late April all were already eating weeds. We think this was a result of a combination of age, some experienced animals, and the social dynamics when animals work in small pastures.
In 2007 several ranchers also expressed interest in seeing if their cows would eat milk thistle. Finding no toxins of concern, we proceeded with a modified plan. Cows ate the thistle in pasture.

Distaff thistle

Distaff thistle (Carthamus lanatus)
This native of the Mediterranean region is a spiny annual that can grow up to 3 1/2 feet tall. We know that efforts to control the thistle began as early as 1871 in Australia, but in spite of their ongoing efforts, it is still reported in every Australian state (1). For more on the plant itself, download this Fact Sheet from Oregon.
Nutrients: Peggy Rathmann harvested a late-growing distaff thistle in October and had it tested for nutritional value at Utah State University. It compared favorably with the nutritional value of Alfalfa, and contained 17% crude protein, 34% NDF and 57% TDN.
Toxins: There are no known incidents of poisoning due to distaff thistle. Based on a report by San Feliciana, et al. (2) the plant contains sesquiterpene glycosides. This is similar to what is found in spotted knapweed which cows were successfully trained to eat at Grant-Kohrs Ranch national historic site. In general, animals are more successful eating terpene-containing plants when they have adequate protein. This could be a consideration as we enter the training phase.
Timing of Grazing: For complete details, visit the Library.

1. G.R.W. Meadly, J. Dept. Agric. W. Aust. 6, 197-201 (1957).
2. A. San Feliciana, A.F. Barrero, J.M. Miguel del Corral, M.V. Gacimartin, and M. Medarde, Phytochemistry 21, 2115-2117 (1982).

Italian thistle

Italian thistle (Cardus pycnocephalus L.)
Carduus pycnocephalus, a vigorous annual thistle, originated in western and southern Europe. It arrived in California during the 1930s and has since become a serious weed problem. It occurs in a variety of disturbed habitats and germinates rapidly and in large numbers. It is most abundant in coastal areas and occurs as a weed of pastures, ranges, roadsides, rural areas, fallow cropland, railroad rights-of-way, field margins, and ditchbanks (Goeden and Ricker 1978). A variety of herbicides have been used on C. pycnocephalus, but they give only temporary control (Wheatley and Collett 1981). Ranchers report that if they cut the thistle, cows will eat it after it wilts.
Nutrients: We have not tested for nutrient content.
Toxins: Though some Carduus species are known to accumulate nitrates in toxic quantities, C. pycnocephalus has not been incriminated as a toxic weed (Goeden 1974).

July, 2006 - New High Quality Feed Discovered: Wooly Distaff Thistle, an article from the University of California's "Grown in Marin" newsletter

June 26, 2006 - Where we're at and results of "Is Molasses the Silver Bullet?" trial

June 3, 2006 - Cows eat Distaff thistle in pasture!

June 2, 2006- Cows eat Italian thistle in pasture! And a little on our data collection

May 2006 - Results of initial training at Wick Rathmann and Gale Ranches

February, 2006 Update from John Wick and Peggy Rathmann

Other Project Resources: Library, and Project Team